About Tensan
(wild silkworm raising)

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Azumino – home to Tensan

Azumino, located near the center of Nagano prefecture, sits at the foot of Northern Alps.
The natural splendor, including clean air and water, still remains here, recalling the nostalgic Japanese scenery of bygone days to our mind.
Wild silkworms have long lived in the unspoiled natural environment of Azumino.
Since their rearing is significantly affected by the habitat environment, our predecessors have had to overcome many hardships over the long history.
Indeed, coexistence with nature has always been our first priority.

History of wild silkworm raising

Chronological table

Years Description
1781~1788 The rearing of wild silkworms started in the Hotaka-Ariake district (then Ariake village) in Azumino.
1849~1853 Silk production started (producing 1.5 million cocoons).
1854~1859 Silkworm raising forests set up (producing 3 million cocoons).
1877 Silkworm growers go to Ibaraki and Tochigi prefectures to help raise silkworms there.
1887~1897 Production peaks, producing 8 million cocoons over the area of 3,000 ha centering around Ariake village.
1902 The outbreak of pebrine and warble flies.
1908~1912 Silk production deteriorates due to the significant damage of falling ash of Mt. Yakedake.
1913 The wild silk production union established (membership: some 200).
1915~1924 Silk production revives, producing four to six million cocoons nationwide.
1943 Silk production suspended due to the outbreak of World War II, leading to the deterioration of the industry.
1947 The Matsumoto branch of Nagano Sericultural Experiment Station established in Ariake.
1947~1972 Wild silkworms raising continued in the experiment station to preserve the species.
1973 The then Town of Hotaka begins silkworm raising by persuading inexperienced local farmers.
1977 Tensan Center built.
1979 Azumino City Tensan Promotion Association founded.
2009 The association has managed Tensan Center as its official manager designated by Azumino City.